Preparing a field for planting crops involves a number of steps. Typically, the field is first ploughed. Ploughing turns a top layer of soil over. Plants growing in the top layer of soil are under the top layer after ploughing. This plant matter can decay to build the soil and provide nutrition for the current-year's crop. This plant matter is known as ‘green fertilizer’.
One or more additional preparation steps are typically performed after ploughing to break up the soil. Breaking up the soil makes it easier for a new crop to establish itself and to access nutrients in the soil and also facilitates planting. A harrow is a tool commonly used for this purpose. One type of harrow is a disc harrow. The disc harrow has a number of rows of disc-like blades that cut the soil as they pass through it. After ploughing a farmer may pull a disc harrow (or other harrow) over the ploughed field to break up the soil sufficiently to allow a new crop to be planted.
Soil compaction resulting from driving repeatedly over the field with heavy equipment can harm the land. Repeated passage of tractors or other equipment can seal off the natural passages by way of which air and water can penetrate the soil.
The field of agriculture is becoming increasingly competitive. Farmers work hard to reduce their cost of production. Field preparation involves significant costs because it typically involves traveling over every part of the field to be prepared multiple times. This results in very significant costs for fuel as well as wear and tear on expensive tractors. Labour costs can also be significant.
Over the years farmers have taken advantage of a number of developments that help to reduce costs of production. One of these developments is the tumble plough. Because ploughs are “handed” a farmer cannot simply plough a furrow to one end of the field and then turn around and plough another furrow adjoining the just-ploughed area. This would result in the soil being turned over in one direction for the first furrow (or set of furrows in the case of a multi-bottom plough) and turned over in the opposing direction on the return trip.
A tumble plough has two sets of plough shares. The two sets are oppositely handed (one set turns the soil over to the right-hand side of the tractor as the tractor pulls the plough ahead and the other set turns the soil over to the left-hand side of the tractor as the tractor moves ahead). Using a tumble plough, a farmer can plough a set of furrows along a field in one direction. When the farmer reaches the end of the field, the farmer can lift the plough shares clear of the ground, flip the plough over to bring the second set of plough shares into operating position, turn around in a U-turn, drop the plough into engagement with the ground and plough another set of furrows immediately next to the just-ploughed area. This significantly increases efficiency and can save both fuel and labour costs in ploughing the field (at the cost of the capital investment in a tumble plough).
There remains a need for methods and apparatus useful in soil tilling which provide further savings in time and/or fuel.